feat: add 9 new dashboard features with export and comparison

- Add Hidden Champions tab with filterable product table
- Add Opportunity Map tab with scatter chart (supply/demand quadrants)
- Add Sales Funnel section to Overview with conversion rates
- Add Price Distribution histogram with mean/median lines
- Add Competition Score gauge (0-100) with 4 sub-metrics
- Add Excel export (3-sheet xlsx) and Print buttons to dashboard
- Add Report Comparison page with KPI diff table and brand bar chart
- Add enrichment UI to ReportList with progress tracking
- Add sidebar navigation with Karşılaştır route
- Refactor UI: Layout, Sidebar, TopBar, KpiCard, SkeletonLoader components
- Improve drill-down UX with visible pill buttons and tooltips

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-panel/package.json

@@ -11,10 +11,12 @@
   },
   "dependencies": {
     "axios": "^1.13.2",
+    "lucide-react": "^0.577.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
     "react-router-dom": "^7.9.5",
-    "recharts": "^3.4.1"
+    "recharts": "^3.4.1",
+    "xlsx": "^0.18.5"
   },
   "devDependencies": {
     "@babel/cli": "^7.28.3",